The proposed construction project will make possible the build out of shell space for an expanded animal facility in Medical Center North (MCN) at Vanderbilt University. Currently, the University is building a three-floor mouse facility on the rooftop of MCN (referred to as MCNII throughout this application); floors six (staff) and eight [mice; Biosafety Level 3 containment suite; rodent quantitative suites; cage washing] will be completed in spring 2002. Unfortunately, limited University resources have required that floor seven (11,000 cage holding capacity) be shell space. Yet this space is absolutely essential to accommodate funded, pending and planned peer-reviewed research programs of existing faculty under recruitment. Several of these programs are multidisciplinary and involve creating and screening mouse models. The University aggressively manages colony size by providing investigators with core functions for mouse embryo cryo-preservation and breeding and colony monitoring. Despite these efforts, there is desperate need of mouse holding space. This application outlines the overall strategic animal space planning at Vanderbilt University. The growth in mouse research projects required the current investment in and building of additional mouse facilities, and a perspective on the scientific research. Funds are requested to build-out what otherwise would be shell space to increase mouse housing capacity by 40 percent.